In it, Edward Deci, a psychologist at the University of Rochester and author of of “Why We Do What We Do,” is quoted:

“It is easy to get people to do things by paying them if you’ve got enough money and they’ve got the necessary skills,” he said. “But they will keep doing it only as long as you keep paying them. And even if they were doing it before, when you stop paying them the behavior drops to a lower level than when you started paying them. We’ve done thousands of experiments on this over 40 years and the data is incredibly robust.”

“There is no evidence that paying people helps them learn — and a lot of evidence that it doesn’t,” Mr. Deci said. Then why do parents — and governments like the United Arab Emirates — resort to paying students? “Because it’s easy,” Mr. Deci said. “It’s much harder to work with people to get them motivated from the inside.”